This test method is the determination of the easily hydrolyzable
chlorine content of liquid epoxy resins. This is a simple
method, hydrolyzable chlorine is saponified with (KOH)
potassium hydroxide and titrated with hydrochloric acid (HCl). Â
PrecautionsÂ
1) Hydrochloric Acid and KOH solutions are
corrosive in nature, Toluene is Flammable and their vaporous can be harmful.
Handle with proper care.
2) All sample preparations should be done in a well-ventilated area.
2. ApparatusÂ
a) Magnetic Stirrer
b) Graduated Pipette
c) Graduated Burette
d) Measuring cylinder
e) Erlenmeyer Flasks
f) Analytical
Weighing Balance
3. ReagentsÂ
a)Â 0.1 N Methanolic KOH
b)Â 0.1 N Hydrochloric
Acid (HCl)
c)Â Toluene
d)Â Phenolphthalein
Indicator
4. Procedure
1. Weigh
between 6.0 – 8.0 gms of Epoxy Resin in an Erlenmeyer flask.
2. Now
add 50 ml of 0.1 N methanolic KOH, then add 15 ml of toluene.
3. Slight
warm and stir to mix.
4. Allow
to cool at room temperature.
5. Now add 3 drops of Phenolphthalein indicator and titrate with
0.1 N HCl. (Endpoint is taken when 1 drop changes
the solution from pink to colorless.)
6) Make a BLANK
determination on the reagents following the same procedure without RESIN
SAMPLE.
5.  CALCULATIONS
                                         H
=Â (V-B) N x 3.55
       Â
          Â
        W
Where
H = Weight (%) of Hydrolysable chloride,
B = ml of HCl required for the titration of BLANK
V = ml of HCl required for the titration of RESIN SAMPLE
N = Normality of the HCl solution
cc. = FACTOR (grams of chloride per mill equivalent
multiplied by the %age factor of  100
W = RESIN SAMPLE weight
Liquid Epoxy Resins Specification
Epoxy Equivalent Weight:Â 185 - 194 g/eq
Color (APHA): 0
- 100Â
Viscosity @25 C:Â 11000 - 14000 cps
 hydrolyzable chlorine: 0.0 -0.05
